Linear cyclic phosphorus-containing polymers



United States Patent 3,239,492 LINEAR CYCLIC PHOSPHQRUS-CQNTAENING PGLYMERS William W. Spooncer, Richmond, Califl, assignor to Shell Oil Company, New Yorir, N.Y., a corporation of Delaware N0 Drawing. Original application Oct. 4, 1960, Sea. No. 60,305. Divided and this application Sept. 29, 1964, Ser. No. 400,194

Claims. (Cl. 26078.5)

This patent application is a division of copending patent application, Serial No. 60,305, filed October 4, 1960, and which has matured into US. Patent 3,160,593 on December 8, 1964.

This invention relates to novel linear cyclic phosphoruscontaining polymers and to a process of preparing said polymers.

It is known that dialkenyl phosphorus-containing compounds such as diallyl phenyl phosphine oxide under certain reaction conditions form polycyclic compounds of low intrinsic viscosity and low molecular Weights. Compounds of this type although they exhibit mild thermal stability are unsuited for use in mineral oils such as fuel oils or mineral lubricating oils because of their poor oil solubility, as well as poor properties with respect to detergency, extreme pressure and stability under severe temperature and pressure conditions.

It is an object of this invention to provide novel high molecular weight oil-soluble linear polymeric cyclic phosphorus-containing compounds. Another object is to provide high molecular Weight oil-soluble linear cyclic phosphorus-containing compounds which possess good detergent and extreme pressure properties. These and other objects of the invention will be apparent from the detailed description thereof.

It has now been discovered that an oil-soluble high molecular weight linear cyclic phosphorus-containing polymer having an intrinsic viscosity of from 0.1 to 2 can be prepared by polymerizing under controlled temperature conditions in the presence of an azo or peroxide catalyst, preferably an organic peroxide and a chloroorganic solvent such as (a) chloro alkyl ethers or (b) chlorohydrocarbons, the former being preferred, a dialkenyl phosphorus-containing compound having at least one P-C linkage, the formula of which can be represented as if M M-P wherein R is an alkenyl radical, e.g., allyl, methallyl radical, Q is a hydrocarbyl radical such as aryl, aralkyl, alkaryl, alkyl or cycloalkyl radical of from 6 to 18 carbon atoms and at least one of the ns is 1 and the other 11 can be an integer of from 0 to 1, preferably 1.

In view of the above it is surprising to discover that by polymerizing clialkenyl phosphono compounds represented by formula (I) in the presence of :an azo catalyst or an organic peroxide at between 50 and 175 C. and a chlorine-containing solvent selected from (a) chloroalkyl ether or (b) chlorohydrocarbons such as chloroalkanes or chloroaromatics that oilsoluble, high molecular weight linear cyclic phosphorus polymers are obtained. By high molecular weight is meant molecular ice weights in the range form 10,000 to 100,000, preferably 15,000 to 50,000 having a plurality of units such as or mixtures of units (II) and (III).

When these dialkenyl phosphorus-containing monomers are polymerized with other polymerizable monomers such as described hereinafter, e.g. rneth-acrylate esters of long chain alcohols having 10 to 30 carbon atoms or vinyl esters of long chain fatty acids or the like, copolymers of from 10,000 to 1,000,000 can be obtained.

The azo catalyst such as a,aazo-diisobutyronitrile is employed when the reaction temperature is low (SO- C.) and the organic perioxide catalyst is used when the reaction temperature is high (80-175 C., preferably C.). The organic peroxides may be aliphatic, aromatic, heterocyclic or alicyclic peroxides, such as diethyl peroxide, tertiary butyl hydroperoxide, di(tertiary butyl) peroxide, benzoyl peroxide, dimethyl thienyl peroxide, dilauroyl peroxide and urea peroxide. The catalysts are generally used in an amount of 0.1% to 5% by weight of the reactants. Peroxide catalysts are preferred since reaction rates and yields are better.

The solvent which is so essential in the formation of linear polymers of the present invention include (a) chloroalkyl ethers such as dichloroethyl ether, dichloropropyl ether, dichlorobutyl ether or (b) chlorohydrocarbons such as chioroalkanes such as dichloroethane, dichloropropane, dichlorobutane; chloro-aromatics such as monochlorobenzene, dichlorobenzene, chlorotoluene, and mixtures thereof. The chloroalkyl ether solvents such as dichloroethyl ether in conjunction with a peroxide catalyst such as di(tertiarybutyl) peroxide are preferred since high molecular weight (15,00050,000) linear polymers are obtained.

Suitable dialkenyl phosphoric compoundsv for use in.

preparing the linear cyclic. polymers of the present invention include monomers having the general formula the same or different but are preferably the same, more.

preferably they are allyl radicals. The above dialkenyl derivatives of phosphonic acid may be prepared by any of the methods wellknown in the art. For example, if R and. R are alkenyl radicals, the dialkenyl phosphonates may be conveniently prepared by reacting the .desired phosphonic dihalide with the desired mono-olefinical- 1y unsaturated alcohol in the presence of an acid sequestrant, e.g., pyridine to produce the diester. When R and R are dialkenyl radicals, the desired compounds may be prepared by an Arbuzov reaction on a dialkyl alkenyl phosphite with an alkenyl halide.

Examples of suitable dialkenyl derivatives of phosphonic acid are diallyl phenylphosphonate, diallyl ethylphosphonate, dimethallyl ethylphosphonate, the monoallyl ester of allylphosphonic acid, allyl methalyl phenylphosphonate, diallyl benzylphosphonate, diallyl phenylphosphonate and allyl-Z-propane phenylphosphonate.

A further class of dialkenyl phosphorus monomers that may be used in forming the polymers of the present invention has the general formula:

where two of the groups R1, R and R are alkenyls. and the other group is hydrogen, alkyl, cycloalkyL'aryl,

aralkyl or alkaryl. Preferably R is an alkenyl or cycloa'lkenyl radical. The alkenyl radicals may be ocZB monoolefinically unsaturated hydrocarbon radicals, e.g., oL-.0I ,B-alkyl substituted vinyl radicals, but preferably the al- If R is alkenyl the [ivy mono-olefinically unsaturated derivatives may be prepared by direct esterificati-on of an alkenyl phosphinic acid with the desired fiz'y monoolefinically unsaturated alcohol. Alternatively if R is alkenyl and both alkenyl radicals in the product are to be. the same, a convenient method of preparation is to react a phosphonous dichloride with the desired fiz'y mono-olefinically unsaturated alcohol to form the diester of a phosphinous acid which partially undergoes an Arbuzov re-arrangement to form the ester of the corresponding phosphinic acid which may be separated from the reaction mixture by distillation.

If R and R are both alkenyl radicals, the desired product may be obtained by reacting a phosphorodihalidate of the formula R P(O)X with an alkenyl Grignard reagent, e.g., R'MgBr (R' is alkenyl) to form R0 P(O) R' Examples of such compounds are diallyl ph0S-' '50 kenyl radicals are firy mono-olefimcally unsaturated hy..-

phinic acid, .allylmethallylphosphinic acid, ethyl diallylphosphinate, phenyl diallylphosphinate and methyl allyl methallylphosphinate, lauryl diallyl phosphinate;

A still further class of dialkenyl phosphorus compounds useful in the present invention is thathaving the general formula:

R1 0 R4 m (VIII) where R and R are alkenyl radicals and R is a.hydro-.

gen atom or an alkyl, cycloalkyl, aryl, aralkyl, or alkaryl radical; R and R maybe azfi monoolefinically unsat v drogen atom or an alkyl group preferably having up to six.

carbon atoms. R and R2 may be the same or different,

but preferablyv they are the same and ,more preferably they are allyl groupsr Exemplary of suitable. phosphine oxides are diallyl phenyl phosphine oxide', dially1 ethyl phosphine oxide, diallyl benzyl phosphine oxide, allyl methallyl pheny'l phosphinet oxide; dir'nethallylphenyl phosphine oxide dimethallyl isopropyl-phosphine oxide.

and diallyl lauryl phosphine oxide.

Mixtures of two .of the foregoing .monomers can be used if desired or these monomers can be cop-olymerized with other polymerizable mono-olefinically unsaturated compounds having an oleophilic hydrocarbon chain of at least 8 carbon atoms with which the foregoing phosphor'us compounds may be copolymerized,.are acrylic acid and u-substituted acrylic acids and their derivatives,

such as their esters, nitriles and amides. Examples of such compounds are C alkyl-substitute d ethacrylic acid, a-dicresyl acrylic acid, the alkyl esters thereof, e.g., octyl, nonyl, 1auryl,cetyl, o1ey1,-i.stea1yl and dimethylcyclohexyl esters, a-ethylhexylacrylamide, laurylacrylamide, a-octacrylonitrile, 2-butyl-2-hexenitrile, 2-propy1- Z-Octenenitrile, 2-chloroethyl-Z-hexenehitrile, 2-ethyl-3- chloro-Z-hexenenitrile, 2-isopropyl-3-bromo-2-octenenitrile, and or octyl-B-cyclohexylacrylonitrile.

Other compounds which may be used to form'the copolymers. used in-the present invention are winy-l esters of organic acids such as vinyl laurate and vinyl stearate; vinyl ethers such asvinyl octyl.ethe'r,.vinyl lauryl ether, and vinyl dicresyl etherrvinyl ketones suchlas octyl vinyl ketone, lauryl vinyl ketone, and stearyl vinyl ketone; vinyl aryl compounds such as ortho-octylstyrene, paralauryl styrene, para-stearyl styrene, and u-octyl styrene; and other alkyl derivatives of styrene'in'which a C3 alkyl group or groups may tbe substituted-in the ring or in the side chain or both. Allyl esters, ethers and ketones corresponding tothe vinyl compounds listed above may also 'be used. u it-unsaturated polycarboxylic acids and their derivatives such as maleic, fumaric, citraconic, ita-.

conic, crotonic, aconitic and tricarballylic acids and their monopolyesters with aliphatic and aromatic alcohols and their amides and nitriles may also. be used.

Other compounds which 'may be used to form the.

phosphorus-containing copolymersused in the present invention are the .oc-"OlfifilJS particularly those having more mono-olefinically unsaturated substituent,je.g., the vinyl pyridines (whether 2-, 3---or 4-substituted)v and the vinyl alkyl pyridines, 3-lauryl-5-vinyl pyridine, 4-lauryl-2-vinyl pyridine, 4-stearyl-2-vinyl pyridine.and '2-stearyl-5-vinyl pyridine. Vinyl lactams are also suitable monomers, particularly the N-vinyl pyrrolidone or N-vinyl piperidone. These vinyl compounds should have at least one C alkyl radicalin the molecule.

Of the above-listed monomers cop-olymerizable with the phosphorus-containing monomers according to the present invention, it is preferred that they contain at least one oleophilic hydrocarbon chain of at least eight carbon atoms which is preferably an alkyl radical of 12 to 30 carbon atoms, and such copolymers per se are a feature of the present invention. Mixtures of the above monomers may be used in forming the copolymers used in lubricating oil additives according to the present invention. Particularly preferred copolymers are those formed from dialkenyl-su'bstituted phosphorus compounds with a higher alkyl ester of an acrylic or methacrylic acid, i.e., where the ester group contains 8 or more carbon atoms, e.g., lauryl methacrylate. Minor proportions of lower alkyl esters of acrylic or methacrylic acids, eg methyl methacrylate, may advantageously be present in such copolymers.

The molar ratio of phosphorus-containing monomer to the polymerizable com-onomer may vary Within wide limits and generally lies between 20:1 and 1:20. Preferably the ratio lies between 1:1 and. 1:20, with ratios between 1:3 and 1:10 being especially suitable.

The following examples illustrate methods of producing polymers and copolymers of the present invention.

Example I About 5 grams of allylphenyl-Z-propene phosphonate in ,8,fi'-dichloroethyl ether solvent (5 ml.) containing ditertiary-butyl peroxide (0.15 gram) was heated for about six hours at 150 C. The solvent was removed at reduced pressure and the residue dissolved in benzene and the polymer precipitated with ether by centrifugation. The de-. sired linear polymer (72% yield) had a phosphorous content of 11.3% and a molecular weight of 26,000 determined by light scattering in methyl ethyl ketone and comprised of a plurality of units rep-resented by When the above reaction was repeated using ethyl ether or benzene as the solvent, the resulting polymer yields were about 15% and the molecular weight of the polymer was around 1,000-l,500.

Example II Diallylphenylphosphine oxide in dichloroethane and ditertiarybutyl peroxide catalyst was heated for six hours at 130 C. The polymer was precipitated with diethyl ether, collected and washed by filtration, and dried at reduced pressure to leave a linear cyclic polymer having a molecular weight of about 5,000 as determined by light scattering, having a plurality of units.

Example 111 One mol of diallylphenylphosphine oxide and four mols of lauryl methacrylate were dissolved in p,p'-dichloroethyl ether containing 0.1% ditertiarybutyl peroxide and the mixture was heated for 24 hours at C. The polymer was then precipitated and dried in the manner described in Example I. The resulting copolymer having units of -CHg-C H-CH;

31:0 l (I) P C was oil-soluble and exhibited detergent and extreme pressure properties.

Using the same procedure, the following polymers and copolymers may be prepared.

*Figures in indicate mol ratio of reactants.

Polymers of this invention which are difficultly soluble in mineral oil can be solubilized 'by copolymerizing with polymerizable monomers containing oil-solubilizing radicals as illustrated by Examples III and VI to VII or by addition of solubilizers such as C alkanols, e.g., lauryl or stearyl alcohol or the so-called OX0 alcohols derived from branched-chain olefins, such as polymers of lower alkenes of 3 to 5 carbon atoms, and copolymers of mixtures of such alkenes, by catalyzed reaction with carbon monoxide and hydrogen in accordance with the conditions of the OX0 process, as is well known in the art. The composition of a typical C -OXO-alc-ohol mixture derived from a mixture of C -olefins, produced by polymerization of a typical refinery-cracked gas fraction of C C.; hydrocarbons is given below.

Alcohol: Percent weight 3,5-dimethyl hexanol 29 4,5-dimethyl hexanol 25 3,4-dimethyl hexanol 17 S-m-ethyl heptanoll 1 6 3-rnethyl heptanolj 5-ethyl hexanol 2.3 5,5-dimethyl hexanol 1.4 a-Alkyl alkanols 4.3 Others 5.0

Other examples of suitable alkanols include 6-methyl-1- heptanol, 2-n-propyl-1-pentanol, 3-n-propyl-1-hexanol, 2,2-dimethyl-1-octanol, 10,10-dimethyl-l-undecanol, 3- isopropyl-l-heptanol and mixtures thereof. The solubilizers can be used in amounts of from 0.1% to 10% based on the total composition.

The polymeric additives of this invention improve various petroleum products such as mineral lubricating oil by the incorporation of a minor amount (0.001% to 10% by weight) of the additive. The polymers are particularlyv useful, especially at concentrations of from about 0.001% to about by weight, in refined mineral lubricating oils, especially in non-ash formulations thereof. Suitably such lubricating oils range from SAE 5W viscosity grade to SAE 140 grade and are derived from paraffinic, naphthenic or asphaltic base crudes. sentative oils are refined high viscosity index mineral oils having a viscosity at 100 F. of 100 to 250 SUS. A typical mineral lubricating oil (X) of this type had the following properties:

Gr. API, 60/60 F. 32 Flash, F. 370 Viscosity index (Dean and Davis) 93 Viscosity, SUS at 100 F. 103

The following non-ash compositions are representative of this aspect of the invention:

Composition A: Percent weight Example I copolymer 0.2 Mineral lubricating oil (X) iBalan-ce Composition B:

Example II polymer 0.2 Mineral lubricating oil (X) Balance Composition C:

Example III polymer 0.5 Mineral lubricating oil ,(X) Balance Composition -D:

Lubricating compositions of the present invention such as Compositions A, B, E, F and G exhibit excellent thermal stability and detergent properties when tested in engines operating both under stop-and-go driving conditions and under severe temperature and pressure condi-' tions leaving the engine in a clean condition, with essentially no sign of wear.

I claim as my invention:

1. As a new polymer, an oil-soluble linear cyclic phosphorus-containing polymer obtained by reacting in the presence of an oxygen-yielding catalyst at between 50 and 175 C., a dialkenyl phosphorus-containing compound having a PC linkage selected from the group consisting of dialkenyl esters of phosphonic acid, and phosphinic acid andphosphine oxide, in a chloro organicsolvent selectedifrom the. group consisting of (a) chloroalkyl ether and (b) chlorohydrocarbon, the linear cyclic phosphorus-containing polymer having a molecular weight in the range of from 10,000 to 100,000.

2. As a new polymer, an oil-soluble linearcyclic phosphorus-containing polymer obtained by reacting in the presence of an organic peroxide catalyst at between 75 C. and 175 C., a diallyl phosphorus compound having a PC linkage selected from the group consisting of diallyl esters of phosphonic acid, phosphinic acid and phosphine oxide, in the presence of a chloroalkyl ether solvent, the polymer having a molecular weight of from 15,000 to about 50,000.

Reprel 3. As a new polymer,;an oil-solublelinear cyclic phosphorus-containing v polymer obtained. by reacting in the presence of an azo. catalyst at betweenv 50 and 80 C., a diallyl phosphorus compound having. a -P'-Cj'linkage selected from the group consisting of diallyl esters of phosphonic acid, phosphinic acid and phosphine oxide,1in'the 1 presence of a choloralkyl ether solvent,the polymer having a molecular weight of, from, 15,000 to about,50,000.

4. As a new polymer,.an oil-soluble linear cyclic phosphorus-containing polymer obtained vby reacting in the.

presence of an organic peroxide catalyst at between 75 C. and 175 C., a diallyl phosphorus compound .having. a PC linkage selected from the group consisting of diallyl esters or phosphonic acid, phosphinic acid and phosphine oxide, in the presenceof a chlorobenzene solvent, the polymer having a molecular weight of from 15,000 to about 50,000.

5; As a new polymer, an oil-soluble linear, cyclic phosphorus-containing polymer'obtained by reacting in the presence of an azo catalyst at between 50 C. and 80 C.,

a diallyl phosphorus compound, having a PC linkage selected from the group consisting of diallyl esters of phosphonic acid, phosphinic acid and phosphine'oxide, :in the, presenceof a chlorobenzenesolvent, the polymer having a molecular weightof from15,000 to about 50,000.

6.v As a new polymer, an oil-soluble linearcyclic phosphorus-containing polymer obtained by reacting in the presence of an organic peroxide catalyst at between 75 C.

. and 175 C., a diallyl aryl phosphine oxide,in the presence of a beta,beta'-dichloroethyl ether solvent, thepolymer having a molecular weight of from.15,000 to about 7. As a new polymer, an oil-soluble linear'cyclic phos- I phorus-containing polymer obtained by reacting in the presence of an organic peroxide catalyst at between 75 f C. and C., an allyl aryl propene phosphonate, in. the

presence of a.beta,beta-dichloroethyl ether solvent, the

polymer havinga molecular weight of from 15,000 to about 50,000.

polymer having a molecular weight of from 15,000 to about 50,000.

9. 'As a new polymer, an oil-soluble linear cyclic phosphorus-containing polymer obtained byreacting in the presence of an organic peroxide catalyst at between-75 C. and 175 C., an 'allyl phenyl-Z-propene phosphonate,

in the presence of a beta,beta'.-dichloroethyl ethersolvent, the polymer having a molecularweight of from 15,000 to about 50,000.

10. As a new copolymer, an oil-soluble linear copoly mer of a dialkenyl phosphorus-containing compound having a P-C,linkage selected fromthe group consisting of dialkenyl ester of phosphonic acid,. phosphinic acid and 5 phosphine oxide and a polymerizableimono-olefinically unsaturated compound containing a C alkyl chain selected from the group consisting of alkyl acrylate ester, vinyl aliphatic carboxylate ester and alkenyl maleate .ester; in

the mol ratio of 20:1 to 1220, respectively obtained by reacting the monomer mixture in a chloro organic solvent selected from the group consisting of- (a) chloroalkyl ether and (b) chlorohydrocarbon as between 50 C; and .1 175" C. in the presenceof an'oxygen-yielding catalyst, the copolymer having a molecular weight in the range of,

from 10,000 to 1,000,000.

11.'As a new copolymer, an oil-soluble linear copoly mer of dialkenyl phosphorus-containing. compound having a PClinkage selected from the group consisting of 'dialkenyl ester of phosphonic acid, phosphinic acidand, phosphine oxide and a C alkylacrylateobtained by react-- ing the monomer mixture in the mol ratio of 1:1 to 1:20,.

respectively in a chloroalkyl ether solvent at between 50' C. and 175 C. in the presence of an organic peroxide catalyst, the copolymer having a molecular weight in the range of from 10,000 to 1,000,000.

12. As a new copolymer, an oil-soluble linear copolymer of allyl aryl phosphine oxide and a C alkyl acrylate obtained by reacting the monomer mixture in the mol ratio of 1:1 to 1:20, respectively in a chloroalkyl ether solvent at between 50 C. and 175 C. in the presence of an organic peroxide catalyst, the copolymer having a molecular weight in the range of 10,000 to 1,000,000.

13. As a new copolymer, an oil-soluble linear copolymer of allyl aryl propene phosphonate and a C alkyl acrylate obtained by reacting the monomer mixture in the mol ratio of 1:2 to 1:10, respectively in a chloroalkyl ether solvent at between 50 C. and 175 C. in the presence of an organic peroxide catalyst, the copolymer having a molecular weight in the range of from 10,000 to 1,000,000.

14. As a new copolymer, an oil-soluble linear copolymer of diallyl phenyl phosphine oxide and lauryl methacrylate obtained by reacting the monomer mixture in the mol ratio of 1:2 to 1:10, respectively in beta,betadichloroethyl ether in the presence of ditertbutyl peroxide catalyst at between C. and C., the copolymer having a molecular weight of from 50,000 to 1,000,000.

15. As a new copolymer, an oil-soluble linear copolymer of allyl phenyl-Z-propene phosphonate and lauryl methacrylate obtained by reacting the monomer mixture in the mol ratio of 1:2 to 1: 10, respectively in beta,betadichloroethyl ether in the presence of ditertbutyl peroxide catalyst at between 77 C. and 175 C., the copolymer having a molecular weight of from 50,000 to 1,000,000.

References Cited by the Examiner UNITED STATES PATENTS 2,659,714 11/1953 Harman et al. 252-498 2,694,684 11/1954 Rogers et al. 25249.8 2,711,403 6/1955 Stiles et al. 252-49.8 2,779,739 1/1957 Spivock 25249.8 2,909,559 10/1959 Lanham 260461 2,963,437 12/1960 Ries 25249.8 2,971,019 2/1961 Ladd et al 260461 3,160,593 12/1964 Spooncer 260-861 JOSEPH L. SCHOFER, Primary Examiner.

H. WONG, Assistant Examiner. 

1. AS A NEW POLYMER, AN OIL-SOLUBLE LINEAR CYCLIC PHOSPHORUS-CONTAINING POLYMER OBTAINED BY REACTING IN THE PRESENCE OF AN OXYGEN-YIELDING CATALYST AT BETWEEN 50 AND 175*C., A DIALKENYL PHOSPHORUS-CONTAINING COMPOUND HAVING A P-C LINKAGE SELECTED FROM THE GROUP CONSISTING OF DIALKENYL ESTERS OF PHOSPHONIC ACID AND PHOSPHINIC ACID AND PHOSPHINE OXIDE, IN A CHLORO ORGANIC SOLVENT SELECTED FROM THE GROUP CONSISTING OF (A) CHLOROALKYL ETHER AND (B) CHLOROHYDROCARBON, THE LINEAR CYCLIC PHOSPHORUS-CONTAINING POLYMER HAVING A MOLECULAR WEIGHT IN THE RANGE OF FROM 10,000 TO 100,000. 